﻿using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Data;
using System.Windows.Documents;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Imaging;
using System.Windows.Navigation;
using System.Windows.Shapes;
using System.Threading;
using System.Net.Sockets;
using System.Net;
using System.Diagnostics;

namespace T03ChatServer
{
    /// <summary>
    /// MainWindow.xaml 的交互逻辑
    /// </summary>
    public partial class MainWindow : Window
    {   //服务端的Socket
        private Socket serverSocket = null;

        //服务启动标志：控制启动与停止
        private bool isListen = true;
        //字典保存多个用户的连接信息   key（用户名） value（Socket连接）
        public Dictionary<string, Socket> clientList = null;
        public MainWindow()
        {
            InitializeComponent();
        }

        private void BtnStart_Click(object sender, RoutedEventArgs e)
        {
            //监听(Accept)也需要新开线程
            if (serverSocket == null)
            {
                isListen = true;
                //初始化字典
                clientList = new Dictionary<string, Socket>();
                //服务器地址：测试使用本地地址127.0.0.1
                IPAddress ip = IPAddress.Parse("127.0.0.1");
                IPEndPoint iep = new IPEndPoint(ip, 18888);
                //创建Socket
                serverSocket = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
                //绑定
                serverSocket.Bind(iep);
                //监听
                serverSocket.Listen(100);
                //启动线程开启服务响应
                Thread t = new Thread(StartListen);
                //后台运行模式
                t.IsBackground = true;
                t.Start();
                //提示信息，异步模式更新UI显示
                TxtMsg.Dispatcher.BeginInvoke(new Action(() => { TxtMsg.Text += "服务器启动...\r\n"; }));

            }
        }
        private void BtnStop_Click(object sender, RoutedEventArgs e)
        {
            if (serverSocket != null)
            {
                serverSocket.Close();
                serverSocket = null;
                //停止监听线程
                isListen = false;
                TxtMsg.Text += "服务停止！\r\n";
            }
        }
        private void Window_Closed(object sender, EventArgs e)
        {
            //窗口关闭停止服务
            isListen = false;
            if (serverSocket != null)
            {   
                serverSocket.Close();
                serverSocket = null;
            }
        }
 
        /// <summary>
        /// 该函数是服务端Socket监听线程的委托函数
        /// </summary>
        private void StartListen()
        {
            //创建客户端的套接字
            Socket clientSocket = default(Socket);
            try
            {
                while (isListen)
                {
                    //阻塞
                    clientSocket = serverSocket.Accept();
                    //构建数据缓冲
                    byte[] bytesFrom = new byte[4096];
                    string dataFromClient = null;
                    int len = clientSocket.Receive(bytesFrom);
                    if (len > 0)
                    {
                        //客户端传来的信息（用户名）
                        dataFromClient = Encoding.UTF8.GetString(bytesFrom, 0, len);
                        //分析协议:"$"标识信息的完整性
                        int sublen = dataFromClient.LastIndexOf("$");
                        if (sublen > -1)//数据合法
                            {
                                //分割，获取有效数据
                                dataFromClient = dataFromClient.Substring(0, sublen);
                                //用户不存在于当前集合中
                                if (!clientList.ContainsKey(dataFromClient))
                                {
                                    //加入字典
                                    clientList.Add(dataFromClient, clientSocket);
                                    //广播新用户信息
                                    Broadcast.PushMessage(dataFromClient + "加入", dataFromClient, clientList, Broadcast.SYSTEM_MSG);
                                    //开启客户端连接线程
                                    new HandleClient().StartClient(clientSocket, dataFromClient, clientList);
                                }
                                else
                                {
                                    //如果已存在的用户，向客户端发送提示信息
                                    clientSocket.Send(Encoding.UTF8.GetBytes("#" + dataFromClient + "#"));
                                }
                            }
                    }
                }
            }
            catch (Exception e)
            {
                if (clientSocket != null && !clientSocket.Connected)
                {
                    clientSocket.Close();
                    clientSocket = null;
                }
                Debug.WriteLine(e.ToString());
            }
        }

        
    }
}